The dependence of reversible potentials on the form of modification of edge plane pyrolytic graphite electrodes in voltammetric studies on rubredoxin and ferredoxin from Clostridium pasteurianum

Abstract

Reversible voltammetry of the anionic rubredoxin and ferredoxin proteins at a pyrolytic graphite edge plane electrode can be observed either by ex situ modification of the electrode with multivalent cations (poly(L-lysine), Cr(III) complexes) or by addition of these cations to the solution. However, poly(L-lysine) binds irreversibly to pyrolytic graphite and voltammograms obtained at an ex situ form of this modified electrode provide convenient reference points for estimation of the thermodynamic significance of solution phase interactions between the cationic modifiers and the proteins. Results obtained show that significant shifts in reversible potential are induced by the presence of free..